We might support shield laws for journalists and bloggers but the actual practicalities of protecting confidential sources are a huge challenge for journalists in the modern era.

It’s of little value having a shield law to excuse a journalist revealing the identity of a whistleblower in court if litigants or government agencies have already been able to detect them using the surveillance regime that is ubiquitous in modern society.

It prompts the serious question: Could the Watergate investigation by the Washington Post three decades ago happen in the modern era? How long would Carl Bernstein and Bob Woodward’s White House source ‘Deep Throat’ (senior FBI official Mark Felt) remain anonymous today?

It would be interesting to hear from Bernstein and Woodward about how they would manage their top secret source in an era of geo-locational tracking, phone and social media e-records, CCTV in private and public spaces, and email logs.

Add to that new technologies like Google Glass and you start to wonder where a journalist could possibly meet in secret with a government source without being caught in the surveillance net.

The volumes of private information held on every citizen by governments and corporations was highlighted in the documentary Erasing David, where the lead character went into hiding and hired some of Britain’s top investigators to try to find him by discovering everything they could about him via public and private files. He found it was impossible to lead a private and anonymous existence in the 21st century.

Our digital trail extends wherever and whenever we conduct business on the Internet. The typical web browser allows countless ‘cookies’ that track many of our online activities. Search engines, app stores, airlines, travel booking agencies and countless other online entities hold all sorts of digital information about us that may or may not be secure or subject to legal discovery in the case of a court action. Some European experts are so concerned about the amount of information about us that is out there and its irretrievable nature that they are proposing a new ‘right to be forgotten’ allowing citizens to have personal data permanently erased.

Law enforcement authorities throughout the world are winning court orders to search suspects’ Internet records. Facebook is a popular hunting ground, with Reuters reporting federal judges in the US had approved more than two dozen applications to retrieve incriminating data from Facebook accounts between 2008 and 2011, leading to several arrests and convictions. The Electronic Frontier Foundation has published a useful online Know Your Rights! guide for US citizens faced with the threat of search and seizure of their devices by law enforcement authorities. EFF attorney Hanni Fakhoury explained the volumes of private information the average citizen holds on their personal devices. “With smart phones, tablet computers, and laptops, we carry around with us an unprecedented amount of sensitive personal information,” Fakhoury said. “That smart phone in your pocket right now could contain email from your doctor or your kid’s teacher, not to mention detailed contact information for all of your friends and family members. Your laptop probably holds even more data — your Internet browsing history, family photo albums, and maybe even things like an electronic copy of your taxes or your employment agreement. This is sensitive data that’s worth protecting from prying eyes.”

Of course, basic password selection and management is a fundamental starting point we often overlook. As the computer experts advise, choose your passwords carefully and change them often. Our laptops and smart devices also have geolocation capability, meaning our very movements can be recorded and abused, a point well explained by the Australian Privacy Foundation. This has serious implications for any meetings or communications we might have with confidential sources for our blogs or reporting.

As the Pew Research Center reported in 2011, more than half of people online had uploaded photos to be shared with others. As facial recognition (‘tagging’) is combined with geolocation capabilities, it means we are leaving a digital footprint via our images. That seem fine when we are just sharing an image with our small circle of friends on Facebook, but our ‘friends’ might choose to download and forward them and, depending on our privacy settings, these photos might well be viewable to the outside world.

Despite whistleblower protection laws and shield laws, confidential sources face lengthy jail terms in most countries if they reveal state secrets because officials might not agree there was an ethical or public interest in the material being revealed. That was certainly the case with one of the most famous whistleblowers of the modern era – the military analyst Daniel Ellsberg who leaked the sensitive ‘Pentagon Papers’ about the true story of the US involvement in Vietnam to the press in 1971. Despite government efforts to stop the publication of the material, the Supreme Court allowed the New York Times and the Washington Post to go ahead with its release. Ellsberg and a co-accused later faced charges of conspiracy, theft of government property and espionage which were dismissed among allegations of FBI wiretapping.

Bernstein and Woodward operated using document drops at park benches and secluded places, coded phone messages and convoluted taxi rides to face-to-face meetings with Felt. In the modern era it is even harder to protect communications against detection by the authorities so you need to take extraordinary steps if you hope to keep your sources truly confidential. The international whistleblowing organisation Wikileaks became famous for revealing the 21st century equivalent of the Pentagon Papers when it released thousands of secret US government files on the Middle East conflicts and broader diplomatic relations throughout 2010 and 2011.

It reassured sources that its high security encrypted submission system using an electronic drop box protected their identity. US soldier Bradley Manning was arrested in 2010 and held in solitary confinement pending trial over the release of the classified material. CNN interviewed several experts about the spate of similar sites to Wikileaks who warned whistleblowers to examine their protocols very carefully if they wanted their identities to remain secret after the authorities discovered the leaks. Some reserved the right to disclose leakers’ identities if subpoenaed to do so.

Reporters, bloggers and citizen journalists should pay heed to the fact that their colleagues have served jail time throughout the world for either leaking secrets or refusing to name their off-the-record sources in court. Equally important are the measures you take to protect their identities in the first place.

Disclaimer: While I write about media law and ethics, nothing here should be construed as legal advice. I am an academic, not a lawyer. My only advice is that you consult a lawyer before taking any legal risks.